The embodiments herein relate generally to a hinge assembly for supporting a blind flange used in various piping systems in the oil industry, heat exchangers, ships, tanks, and the like.
Medium to heavy-duty blind flanges are used to open and close piping in a variety of industries. In many applications, the blind flange serves as a cover that is pivotably mounted to a weld neck flange that is welded to a pipe end or opening. The weld neck flange comprises a central opening that is aligned with the interior opening of the pipe. The blind flange is swung open to access and/or perform maintenance on the pipe. These pipe components can be heavy and difficult to maneuver.
In many instances, a crane or alternative heavy lifting equipment is required to swing the blind flange open and closed. This is inefficient and a burden due to the additional requirement of using specialized equipment. There exist a variety of structures disclosed in U.S. Pat. Nos. 7,931,168, 4,519,519, 4,297,072 and 4,865,513, which disclose devices used to mount blind flanges, hatches, manway covers, and the like, to openings in pipes or other tubular structures. However, these devices are disadvantageous because they require the use of multiple parts that are complex and/or bulky. In addition, several of these devices require additional equipment such as booms or clamps. In addition, these existing mounting components are limited because they do not easily accommodate flanges having tolerances on the thickness.
As such, there is a need in the industry for a hinge assembly for use in pivotably mounting a blind flange to a pipe weld neck flange that overcomes the limitations of the prior art. There is a further need for a hinge assembly that can easily accommodate blind flanges and weld neck flanges having tolerances on the thickness. There is a further need for the hinge assembly to permit a user to manually open and close the blind flange relative to the pipe weld neck flange without the need for specialized equipment. There is a further need for a hinge assembly that will permanently remain on the blind and weld neck flanges to permit access to the pipeline or vessel to perform frequent maintenance.